SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '416948f4233d94e10ca0b92ff7d30a22575a883123cc0712ffa6df353e7ccc95' 
  AND token = 'hiWU+XscDMOzwygMRaBlteQb4kyZg9Ek21Te5pVCuvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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