SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6fa54bb0e5b68c07f1b73fc4ad79f251959436828010afaa9a466b266b69379' 
  AND token = 'retpEPohXYWCGVjjO1MoSkNgMQGbc2Hhx6ClNGteLVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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