SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c96e800cebc845f7aab679c18b287a72b4faecc78dc8407b07717190d9112ea' 
  AND token = 'DQpPtgmzzVssmNCzsE5QtTLyscR5SD8LpgtLUE6VPvQ=' 
  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"
    }
  }
}