SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89ea7784de81fad9170e0bf9aa71cdb3c03679e831df77c8378d51134f0b8558' 
  AND token = 'KdgJJn1TaqZyevshiomFFQspLoru9QmBxNJQpxJwl1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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