SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb2c1c92d634498801768151fa3347b6695fa0383b17adcff584b0fd69f161ae' 
  AND token = 'ShOtuKzAbPqer1pUDNaEvLHSYcDy0CXIa5wtPbPrluo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}