SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '371aefe61f96db13423da52f735784d2c42103570ef929fd99d54b0e4a561b56' 
  AND token = 'tdvT9VP7/vvK7vPKgusDPrRRin0nuMtkuSjnfiaJdlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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