SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c135f6a27411a771cdbb6628b4a94cd67252cf8e4c4461d9f9ecfa848cc8b34' 
  AND token = 'QgdjBv/IAUrXeXi2ECebS3rnveYPMMYIxhncPZorWtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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