SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8edb7120e83129764676b2198ffbb34aad86a84100973de29fee4e78889b5983' 
  AND token = 'M56tSV3t8m+Rpb8PzMIjrKItbmzxOHje7RPQScaRcmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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