SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59dea7c02664b2d2ad2bbf3607e791ab1a6136e082e3a1cd483ce0a0cf1419e9' 
  AND token = '0IG2AoKPMBZvb0osT240I7wDMkg+dVDe10GNZpFziak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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