SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7167f4aaf3e90fccfc7953b42ddad7d36145709d5d2d95165a853903942fd747' 
  AND token = 'gRlO7kO9pakdxZ9rw05ydn44HE/SqrMXdvLjmsqa//s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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