SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd43dfd5d0f0559458c319a0eeb00822228a389dd0bad76dcc68575133fa3956' 
  AND token = '64daU//TAKSXzx4GMBvJVl1gp/01jYuEcbwobqt1Fk4=' 
  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"
    }
  }
}