SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c41dc6b7a2134da230599d2e5fcf929e75040675266fe4b6a6e0a330f5aa0d4b' 
  AND token = 'vJTCMJDkcfs1y2KU//nMqOzDXufHnamR/uMRcZo6tkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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