SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43d95c0878bdbe67df6b71d8ff8cb89766aedd3d39e5e8bfcc7173cc91589468' 
  AND token = 'W1xYEQ26FKrYAFQPEpggO/myKPgvD0RAj4+oXVK3cb0=' 
  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"
    }
  }
}