SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e040544f21b6e39580c5d9162f907642f2087aab1c50f378467be94a666014bc' 
  AND token = 'uDqnsyvPGJzniViVaEMxXA6Q9goRLP5l6jnbAZBJU64=' 
  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"
    }
  }
}