SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa3ff9f98cbb68263e5524773efbf34e70cb3f244ff24b92f67f202f726a3c96' 
  AND token = '6X5PuFAQJ6phUqRgQ8LHIgbADJNTyeykjPREU3yEnE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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