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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d2ecc4809d4df84f17947869a4b257109ba0a4aac8ad83a7e8ea96915458eba' 
  AND token = 'u+4Yjb9o/Ctv/GM0Y9n7cGH+6zeB44Wu3yz7gBVK3VA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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