SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dd8bdb441f0eb59b98f7dbbb22c90051aac284284ac1f3e4c409f0a072cff4f' 
  AND token = 'RqlMzbTO91LZoemod8qhjzqCAm90uuhFc/4cCR1goUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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