SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b760c3710da6046a822bdf19bd3ab3c0636aaf6388306943474d5ea378477f3' 
  AND token = '+OghbVMi/UOI5VYMVWVbqSEKHUSUYBYLdJwljYFqVzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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