SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c609f54a6645d0570b75a31d1b831f33a634491a88e071fecf089896bf66e49f' 
  AND token = 'dLArwIeTM++eP9Ps+uPOIjUYoowXIZZcN4h/N1aej94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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