SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c96cb5e47fa5d6314a249eb48d81c918cd6bb57e53e826524848dfd7aa32439' 
  AND token = 'L1wAoInnlZSGkKfWQCjXLVHRBmYpmGLRcJ/kETw3BEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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