SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06dc42f4e64bbc1d922cf59848a18fa54ee76baff16d09a048c6f2c3e525d003' 
  AND token = '5KIpP7x4WK9S/sh2LAxR0hvhmnmCOyA3uXMTMQuQNic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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