SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'abec2a220d3bafc383f4448a2e40931d2b9373f5718b367bced1682fd98b691f' 
  AND token = 'vZn46wt2ADZFl30vnjv9dDou9L3rRkWyfYz4iRDbaKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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