SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1d91193ce535f3eb09cc58726890eb483048618efc0bd3bab3a77668033d5a6' 
  AND token = 'OpW8atNxYW62pntP98/HaKQXl2Kv05PeYGUlaYW7M0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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