SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55dca4799f37dca7a85aabcc6a3186dbbea0f2946c0ff368bb33f344dbfdda04' 
  AND token = 'P3zCknakthFPFM6BquLj8HdOT3PN4SgupJermIj/atY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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