SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c88e4ca653ad5d8f5ec49ca95d6a42165e3910c881648845247799c148d0608' 
  AND token = 'CRVSAyXSGnea/RYbWnatHesqVb1F2QkdFTo+C7rLKHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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