SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf9d25e85c103181b546be3349757585dcffc3ba3b2014a99bab0b63050157e4' 
  AND token = 'm1LlqXkhFAC7XPy90PaRrImpOjC3SD7n/Zmbu6McHXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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