SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd97378ec580cd48a1bcd0191148a4a6120d69d523de3f5eeb32e2f48a9aded7' 
  AND token = 'OdOF6WSZJvUI6EnfBzdtRwNpMj/fwnrQcqHUoScWbz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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