SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b11b4d16cb4d9050edd58cfb4850b234117c9574619d77fc3f4eecca9c1bab43' 
  AND token = 'xd0km2llN8CwZVP/7ZL3rd7o/GhbotBOPdusY839rEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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