SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b33a588088b3bc201de3c91f9395371138f96fc98fa620907eb9ddb2ecfb41a1' 
  AND token = 'k95FhAtvfKWbz/jExt2jW1O7V8N6fsfeyZ+Kcpwwyh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}