SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7e64825e1b239df5d28725abcf627ae33d457b6a374af49a05905dd2032db89' 
  AND token = 'YqyZxGQ9ZVry+RNPIlmPbGciWq/gHOQl++kjK6MXXWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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