SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b45a97db73dcbabe93e53aafea61874138e1ff8938c43f619662b16370e75117' 
  AND token = 'el1Y0JnrVO8EHGswbNiYFmFtCtClE6B0LDx2zBWnffQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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