SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcb5eb9afdc47c6eb407ecea97a1d3e069a7c911204906f4d1afd8118bca45ac' 
  AND token = 'pQ7PsdvrIo6sSaWI4SkiklIveinBdEH/LT8LFrGghfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}