SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf95979a1995b769ddc7973b7cc0aa7e2d785f1698679c2b9c23c836a375b0b' 
  AND token = 'rkQwF6EXMSH9Q4NT/giJiAzjS2v9c472xcWrDl0hr8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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