SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b66611acc6efa7d603ecbcab5f19b821a633f842a36769aa103a5873c77a238' 
  AND token = 'jV1P/1GQsgqrCiVn2SZ6GOj63M0pdiqtCjXqO0x5szs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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