SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7721009d3a346ecc004265e45538d2ac649904c3646d433e36481d6ecacd313e' 
  AND token = 'MA1a9/O+qMBm8nsDJAIZwG1ALpszu0ntYWSNkRKNHtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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