SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2bc507efc0e3bce3ca781263c7d8efb164be51ca1e4d8936c353898dc780d1e' 
  AND token = 'ORGPTO91zRaPXnKLRpRw+oUQxGRYvZXrkVF0aBvwqZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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