SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ef1731608ea3a249ee469f22629ebdbfcc1abda10d470dacd7593d4c59b3d6c' 
  AND token = 'WTkyYM7g3sUL3lp7AAJaz+jmifoCBH4vpg7wHXDeVCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00261

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}