SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '975133c4b348a29e5f779b407375ac8e38c43492c547712456928a1719c00563' 
  AND token = 'pM4Q2xUz7RRcYBC3W9nJcENfAxfQW1GzuTQzoDz1Ylc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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