SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '197a8948376f205526bc078edcde666dc871dc865bd897284294b48eb3c1c99a' 
  AND token = 'ICEBCwyvYy+z7dqmJauXXF8kY5RhbKsQ3eU7w46emK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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