SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad2989f8b4acd8b0b0940b9f2b8993651cf17fc1f9d54a2b70070b98948409f5' 
  AND token = 'wR9HhnWsJKQwwEOZJU3gOHSZWhWYZ9vmD11w6zqmoMg=' 
  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"
    }
  }
}