SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f680b881fb54cdce12ea0b89d1a2f05d17e0da3ca6594ce71dc98a3ac46b1795' 
  AND token = '/K7FLDvCq6xxbNb4OzWBLUpAfhTT2e0Pqgcii6cnO5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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