SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54006a8bd7eaf5cfe1c614f03fe810b99b66545b1d4788bf1305dea7f4474752' 
  AND token = '9sN8lXSRHn43L6Me2dXJrDjgToB1CkhpiwMOpnY1ii4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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