SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '994fa75286d7f7f50ebbf59ae36796a99ab811f6b77bc04c2de436dde18a200e' 
  AND token = 'aMbyC78TvNrRlKLJTb1PCLQV1JzVGWFWJcb/HyN9D/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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