SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4efbddd80a97629a16279db42291fd1154140cf93911f3ec0bdd63a658296b9f' 
  AND token = 'ohNrGOFg+1BHh/z94zvY+CLxJlm86y92uLSh34ZBImk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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