SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3f0b315d9255330f2c4725784cc9853466bb4a49a3d2aaa387b28ba2de59a2a' 
  AND token = '2ZMYqegJv2IrFQFMzcDRhU7H2rTka1oXnKWyGAaxEIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00098

JSON explain

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