SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18290c88503888cf203da98e2b4cdb9e3cd41b14aad3ae5558190eea7c52aaaa' 
  AND token = 'hwzkU0uw+bGWeL9yxHupbeeNaOHQB0AD+kSjlixYRG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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