SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96bee964536233408723c6f07d7b1b804835cd7d38c8e6c63e977ea9dc7c9da3' 
  AND token = 'sMUq6Ytb/qDHNNsGZjdzjbC/bmkfxsEIBscQ0LJt4Lo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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