SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f00bf4570b18e4d1fa87fadc4eae1ecf70d54bee914538fcc6b5162471fd5cb' 
  AND token = 't8DI7exo4k4bXP8vzDyqQwS/kV3Lm6qtHlUvX/6hmn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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