SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86575093072162366d89ab7ed56bc6a7032405b66adc3817a523d0eb2a2235fb' 
  AND token = 'Q6DovcjjBWC9uk23Bi5NlmdY2VPsfG0QoefmyTn2NFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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