SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '197b116b4c5f68bd154cab49a0cfe34a5da54fbb8ab8468fcb7123da435ca69d' 
  AND token = 'kICTXovLKqvCf17hP1KWN9m/hh788o9TsS6gPG4Ottk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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