SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c20eced02f3a6e8dbf2a3bbe14bcd26e2f732ceb5352d6b30d39277c0445ea8b' 
  AND token = '2f+7XgLvfmSsuuF9Zxp+/OD+qsv/J8YrJzaGsrh1tvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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