SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f0f0297d68616bed61592e744891cc1d647abdc19827c5d62a5550932afa3f1' 
  AND token = 'hO9OB83qs/Tj83HyxmbGxLapsKc2iZyiuyEQVyTJRho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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