SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e73104500ff346f4b83c56cb8af8de5d4578eabebf106345d2c1f3507158cc0e' 
  AND token = 'v8ULpQz3QfPXV2e0eKN4HmL+YCZ73FtmS4slREoWSos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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