SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c148290ecbecf31fd362a109bdcaa0125e171a786ea6a7926d41496cf16a77f2' 
  AND token = 'kFdJTzutWFui2ErUVS4YJvOQpYh6024rW1ndSU8aGXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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