SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2246aa089f15920b9ea91635d674ae3fb4154e6ca4272bd04778aade3f45111f' 
  AND token = 'eUPBkBUjNLSH+0wNVhhfCKFkcGS2ojIEBTjhIDMyCuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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