SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3dfd7fee4995dc7810bb3cb812899b01ef2e22ca3974093110bcd8c0c9eba4e' 
  AND token = 'hhtzdHax1c0Kxp1YlQEFBEn1AEBOzPOmJrqUno7OZ5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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