SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a9ece32f1ac72e01984d1e908bb22a077e815fa74cd69bb82a96767bfc335be' 
  AND token = 'qNWhnOGhQ5K3Dftotz/ZCRQnciQsOtBF+AqNbP/W6pk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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