SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5073a5cca13cb9ff4270005db2f305df7529bec0f5ee51c043ff02af5b7adee9' 
  AND token = 'BxZWIsAw9rSyIUyiDvZmyru46s59xEcjj288/wHtR30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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