SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5460a4529f760e691cbf883adf3c8aeeb29b211e44ce5f16fd7ef0e9996e5a4' 
  AND token = 'hS62KDKMq91c+nvqLoOB2AERqAaouiPq4T+S/vziVO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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