SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1650d6f68ef69b4bd35c34dfac52d6aaac143e67172db558413a9da51b0182d' 
  AND token = 'jLiFqejz4YyfD32uqwoiAGzEZINU+i9ihwtBvSfRXWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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